This invention relates to image projection and television viewing systems. More particularly, this invention relates to a method and apparatus for enabling a centrally located televised picture to be viewed substantially simultaneously by an audience surrounding the picture over 360.degree..
The general problem in the display of a picture print, a television image or a projection onto a screen is that the picture is best viewed when the viewer's line of sight is precisely normal to the plane of the picture. This ideal condition is difficult to realize when several people wish to view the picture simultaneously from varied locations.
One solution to this problem is to simply mount the picture on a rotating pedestal which will slowly rotate over 360.degree., permitting several people surrounding the pedestal to eventually view the picture in a line of sight normal to the plane of the picture. Such systems are often used in advertising displays within large areas such as railroad stations and the like. A problem with such an arrangement is that the rotation of the picture must be relatively slow in order to permit the various viewers to have an opportunity to study the picture. Such a slow rotation means that essentially only a few people at a time are viewing the picture while others out of the line of sight must wait until the picture comes into view.
There are many instances in which several people may wish to view a picture or displayed data simultaneously and continuously so that they can all carry on a meaningful discussion concerning the displayed information. For example, during business meetings a group of executives typically sit around a conference table, an arrangement which does not readily enable information presented on the table to be displayed to all in attendance. A great benefit would be realized if a means centrally located on the table were available which would permit everyone present to examine a picture or projected data substantially simultaneously. For example, the necessity of passing among the members of the group pictures to be successively viewed would be avoided. In addition, the ability to display data through a 360.degree. range would prevent members from looking at a series of pictures out of order, a potential problem if duplicate sets of pictures were to be provided to each individual member.
Another drawback associated with conventional display systems is that special consideration must be given to the positioning of the display within its environment because, typically, conventional display systems, such as a television, cannot be viewed from the rear or extreme sides. Thus, the area within which a viewing audience can be accommodated is limited to locations with suitable sight lines. As a result, use of the space available around the display system is often limited by the presence of blind spots. Moreover, the positioning of furniture within a room can disadvantageously be dictated by a need to provide clear sight lines to a television or the like.
In an attempt to overcome the viewing limitations associated with conventional displays, 360.degree. viewing systems have been developed, an example of which is shown in U.S. Pat. No. 3,976,837. Although such prior 360.degree. viewing systems have provided significant advancements over the prior art, additional features have been considered desirable in order to provide a more commercially acceptable product. For example, in some applications it may be desirable to minimize the moving parts of the system.
There exists, therefore, a need for a visual display system that will enable an entire audience to view a televised picture simultaneously, regardless of an individual's location around the display system. Additionally, an improved 360.degree. viewing system is needed which utilizes a stationary cathode ray tube and optical means to rotate a projected image in space. Such a system would preferably be of simplified construction and would maximize the size of the projected image with respect to the overall physical housing for the viewing system. Moreover, a 360.degree. viewing system is needed which provides a novel shutter arrangement that tracks the projected image in space as it is caused to rotate. The present invention fulfills these needs and provides further related advantages.